Insert specific unicode symbols inside values of data.frame variable

Question

In my data.frame I would like to add two variables, "A" and "B", whose values contain respectively an n with the i subscript and an n with the s subscript.
As I have understood so far, it's not possible to specify an expression for the values of a variable, and hence to add special characters it's necessary to use unicode symbols. Some of this unicodes work in R, as for example the greek letter "mu", identified with the unicode \U00B5, or numeric subscripts, as you can see in this reprex in your R console:

x <- data.frame("A" = c("\U00B5"),
                "B" = c("B\U2082"))

print(x)

These unicodes work also if I decide to put this variable in a ggplot() object, because I will display the correct symbol ("mu" for example) on the axis text or the facets.
The problem is that when I do the same for the subscripts of i (unicode: \U1D62) and s (unicode: \u209B), R doesn't recognise the unicode and prints the whole string inside the variable name.

Do you know how I can resolve this issue and if this unicode works on every operating system?

Thanks

Answer 1

Is there a reason you can't use the expression() function? It seems this would solve your problem (at least concerning greek letters).

Here is the site i used to learn how to input greek letters into my R/ggplot-legends.

https://stats.idre.ucla.edu/r/codefragments/greek_letters/

Altough it is not exactly the answer you look for, i still hope it helps!

Answer 2

If you are on Windows 10 recently updated with as of April 2018 Update: Use the Windows key + '.' (e.g. hold together Windows Key plus period) in your text editor. This brings up Microsoft Emoji keyboard. Select the Greek letters variable for your script. The R Console will not accept the Greek letters as variables directly but only the from the editor script. Some of the Greek letters don't translate to English (like "µ" or "ß".) You can paste and copy them from ls() output to access. You may be able to use some math symbols as well for variable names. I can't however, get this to work with source(). That must be a text encoding problem.